Well there have been numerous problems with the ActiBrake
(no longer in business)hydraulic pump that actuates the brakes. Luckily that is the one brake system problem which I have not experienced. Howerever I have had problems with brake hoses and a disintigrating brake pade which ruined a rotor and you can read all about htem here...
Hopefully I have all the bugs worked out of the system.
I do like the way the hydraulic disc brakes stop the trailer. I just wish I hadn't had these issues to contend with.